Our general objective is to further our understanding of the phonological component of language users' linguistic competence as it functions in speech and reading. The proposed research continues a line of investigation that has produced notable discoveries that have advanced our understanding of 1) the mechanisms of speech perception and production, 2) the role of phonological coding in skilled reading across contrastive writing systems, 3) the centrality of phonological deficits in reading disability (RD), and 4) the neural circuitry associated with skilled reading and with atypical reading development. We propose to employ a variety of methodologies (including fMRI, NIRS, and computational modeling) to address three overarching goals. First, to develop an integrative computational framework that explains the nature of phonological processes, the role of phonology in reading, and the association between phonological impairments and difficulties in learning to read and second, to extend this work, heretofore centered on word level processing, by examining those cognitive and neurobiological processes that contribute to individual differences in comprehension (understanding meaning) of spoken and written language. Third, culminating years of research on the phonological deficits in reading disability, we employ longitudinal tracking and integrated brain/behavior measures to test a specific hypothesis that places the origins of reading failure in preliterate children directly in the brain mechanisms for speech perception and speech production.